TABLE 3.
Distribution of Direction of Effects by Correlation Category and Distribution of Effects (5 levels) by Level of Estimation Required (5 levels)
| Direction of Effect |
Level of Estimation |
|||||||
|---|---|---|---|---|---|---|---|---|
| Category of r | Negative | Positive | Unknown | 1- High Estimation | 2- Moderate Estimation | 3- Some Estimation | 4- Slight Estimation | 5- No Estimation |
| Bivariate | 3 | 14 | 3 | 0 | 3 | 1 | 3 | 13 |
| Autoregressor-only/lower estimate set | 4 | 25 | 17 | 4 | 12 | 5 | 9 | 16 |
| Autoregressor-only/upper estimate set | 4 | 25 | 14 | 1 | 12 | 5 | 9 | 16 |
| Autoregressor plus covariates/lower estimate set | 4 | 16 | 25 | 6 | 19 | 0 | 12 | 7 |
| Autoregressor plus covariates/upper estimate set | 4 | 16 | 22 | 4 | 19 | 0 | 12 | 7 |
Note. In a small set of studies, both lower and upper estimates of effects were calculated to prevent bias that is due to choice of estimate. Lower and upper sets are reported separately.